java字符串壓縮編程問題

給定一個字符串aaabbbccc，編寫一個函數使其壓縮爲a3b3c3的形式。

public class pressal {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String str = "aaaccbbb";
		System.out.println(method(str));
	}

	private static String method(String str) {
		// TODO Auto-generated method stub
		String arr = "";
	
		int count=1;
		char s1=str.charAt(0);
		for(int i=1;i<str.length();i++){
			char s2=str.charAt(i);
			if(s2==s1){
				count++;
				continue;
			}
			arr=arr+s1+count;
			s1=s2;
			count=1;
		}
		arr=arr+s1+count;
		return arr;
	}

}